Thermoplastic and fiber-reinforced thermoplastic composite structures and parts are used in a wide variety of applications, including in the manufacture of aircraft, spacecraft, rotorcraft, watercraft, automobiles, trucks, and other vehicles and structures, due to their high strength-to-weight ratios, corrosion resistance, and other favorable properties. In aircraft manufacturing and assembly, such thermoplastic and fiber-reinforced thermoplastic composite structures and parts are used in increasing quantities to form the fuselage, wings, tail section, skin panels, and other components.
However, the use of thermoplastic composite materials in the design and manufacture of tubular cylindrical and non-cylindrical structures, such as tubes, pipes, ducts, conduits, and elongate hollow components, for use in aircraft, may present certain difficulties. For example, difficulties can arise due to tooling removal, processing temperature, outer surface dimensional tolerances, fiber alignment, and other processing challenges. Although certain known methods may exist for fabricating tubular cylindrical and non-cylindrical structures, such known methods have certain perceived disadvantages. For example, certain known methods may use only discrete load introduction fittings and parts after overbraiding the fabricated tubular cylindrical and non-cylindrical structures. Consequently, such known methods may require a failsafe redundant structure, which may include a primary weld of the fabricated structures. Aside from this primary weld, a wrap of the braided fibers may further be required to manufacture the fabricated tubular cylindrical and non-cylindrical structures with one or more load fittings or load introduction points.
Therefore, manufacturing options for such known methods may result in increased manufacturing time, and in turn, increased manufacturing costs. Further, the failsafe redundant structure typically may result in increased weight of the aircraft, which, in turn, may result in increased fuel costs during aircraft flight.
Accordingly, there is a need for improved thermoplastic composite tubular structures that can be embedded with one or more load fittings. There is also a need for improved methods for manufacturing such thermoplastic composite tubular structures embedded with load fittings that provide advantages over known structures and methods.